Method and apparatus for making friction linings



D. W. FETHER Aug. 27, 1%35.

METHOD AND APPARATUS FOR MAKING FRICTION LININGS Filed Sept. 5, 1955 Invent v Dwzaid fi/fwher.

Patented Aug. 27, 1935 METHOD AND APPARATUS FOR MAKIN FRICTION LININGS Donald Fether, Downey, Calif., assignor to Emsco Asbestos Company, Downey, Calif., a corporation of California Application September 5, 1933, Serial No. 688,171

IZiClaims. (Cl. 13 9---36 This invention has to do with improved methods and apparatus for incorporating in friction linings, brake and clutch linings and the like, sub' stances calculated to give to: the liningcertain desired frictional and other properties. In certain of its phases the invention deals particularly with the impregnation of woven linings, while in other of its aspectsthe invention is broadly applicable to the treatment of friction linings in general.

It is customary practice to impregnate formed friction linings with drying oils, coal tars and other oils commonly referred toas friction compounds, to obtaina desired coefficient of friction between the lining and drum, and among other purposes to preserve the flexibility of the lining. The usual method of impregnating the lining with such friction compounds consists in first dissolving the oil in a volatile solvent, then impregnating the lining with the solution and finally volatilizing I the solvent to leave the heavier drying oil in the lining. Now this method has certain distinct disadvantages both with respect to the quality of lining produced and the time and labor consumed in the impregnating process. In the first place, by reason of the dilution of the oil with the solvent and the necessity for having to use thinner drying oils by the old method, it is found that the oil,

remaining in the lining after volatilization of the solvent does not have the thick consistency most tobe desired. Experience has shown that best re suits and best linings are obtained in proportion to thickness or viscosity of the drying oils. Second, the usual method involves, as stated, the necessity for driving off the solventfrom the impregnated lining, and particular care must be exercised in volatilizing the solvent so that the solvent will not, by too rapid volatilization carry the drying oil from the interior of the lining toward its outer surfaces and thereby destroy the uniformity of impregnation. While in all cases, as in the present process, it is necessary to subject the impregnated linin to a final baking at fairly high temperatures, the above mentioned customary methods of impregnation involves, in addition, a separate heating operation prior to the final baking, for the purpose of driving off the solvent.

In making woven linings, it is desirable that the impregnating oilsbe applied to the yarns at substantially the point of weaving, as in accordance with the hereinafter described method. If it be attempted to first impregnate the yarns with drying oils, and while the latter are still wet and s icky, to then weave them into the lining, difiiculties arise to render such procedure entirely irn-' practical. ,Forexample, the heddles will become so coated with the viscous impregnating substance as to render it impossible for them to properly handle the yarn.

In accordance with the invention, I obtain cer- 5' tain distinct advantages over prior methods, one of the chief advantages'being that I am able to thoroughly and Uniformly impregnate the lining with thicker friction compounds than can be put in by a carrier s0lvent.- I am also able to dispense l with heat treatment of the lining except the final baking operation, with resultant substantial reduction in time, labor and manufacturing costs. Furthermore, no particular care is required in the single heating to which my impregnated lining 15 is subjected; it may be rapidly brought up to'bal ing temperature without affecting the evenness of distribution of the frictioncompounds in the linmg. I

In making impregnated woven linings, I intro 20 duce the friction compound to the shed between the warp yarns at or near the weave point and in advance of the weft so that on each stroke of the reed, the friction compounds are driven into the lining. I preferably feed the friction compound intermittently and in timed relation with the operation of the weaving mechanism, and obtain satisfactory results by subjecting the feed to in termittent pressure impulses. I also preferably employ a movable friction compound supply conduit adapted to be projected into the shed between the warp when the reed is in open position, and to be Withdrawn from the shed as the reed comes forward to contact the weft; 3

The above features and objects as well as additional objects and. details will be fully understood from the following description of certain typical embodiments of the invention. Throughout the description reference is had to the accompanying 40 drawing, in which:

Fig. 1 is a general diagrammatic View illustrating one form of the invention;

Fig. 2 is a fragmentary front elevation as viewed from line 22 of Fig. 1; 45

Fig. 3 is an enlarged fragmentary side elevation of the carrier looking from line Zi-3 of Fi Fig. 4 is an enlarged transverse section through the friction compoundcarrier; 50

Fig. 5 is an enlarged'sectional view of the drying oil pump; and

Fig. 6 shows a variational form of apparatus for effecting intermittent discharge of the drying oil. 55

It is to be understood that the illustrated mechanisms are merely typical of various devices by means of which the invention may be put into practice, and that various changes and modifications may be made without departure from the intended spirit and scope of the invention.

In Fig. 1 I have shown only those parts of the usual weaving mechanism that need be illustrated for a full understanding of the present method and associated apparatus utilized in carrying out the method. The lay beam J28 pivotally mounted at H for oscillatory movement 'between the solid and dotted line Illa positions, is

shown to be driven by link 12 from a .power unit conventionally illustrated at H. The warp, con sisting of upper and lower courses [5 and E6 of yarn, extends through opening 14 in the lay beam and through the reed H. The lay beam carries the usual shuttle i8 which travels back and forth in front of the reed and carries .the weft yarn it. The warp converges toward what may be termed, for convenience, the weave point at 253 and is there woven into "the lining 2! which is advanced over a roller v 22 mounted on the breast beam 23 and led down to awindingreel 24.

The impregnating friction compounds are .applied to the yarns at or near the weave "point, from a movable carrier, generally indicated at 26 and which in the typical :iorm herein illustrated comprises a container '21 carried on arms 25 pivotally mounted at 29 on the breast beam. Drying oils are .fed into the forward compartment 27a of container 21 through a pipe 28 leading from pump 3%, the pipe .leadi-ng :into compartment 2% through one of its end walls as indicated at 38. The liquid is discharged from compartment 21a through a plurality of downwardly projecting nozzles 3! having tapered points Ma and central fluid courses 32 opening at opposite sides of the nozzles through holes 33. When the carrier and nozzle assembly is in the operative solid line position indicated in Figs. land 2, the nozzles are projected into the shed 3 between the warp and also between the yarns of the warp courses i5 and i6. Preferably the nozzles are projecteddownwardly within the shed a distance such that the fluid discharge .open ings 33 of the nozzles will-come opposite atheyarns of the lower warp l6. It will be understood that the lining may be woven with two or more plies and. that the warp courses maybe increased ,correspondingly. In any event however it is [preferred that the nozzles be projected-down through the shed a distance such that the fluid .being discharged from the .nozzles will contact the yarns of the lowermost warp course.

The carrier and nozzle assembly is intermit tently moved, in timed relation with the operation of the lay beam, between the :solid line and dotted line positions shown in Eig. 1, by means of link 35 pivotally connected at 35 to the lay beam and having a ,pin-and-slot connection at 3? with an upward extension 33 of one of the carrier supporting arms 25.. .As the .lay beam swings toward the left and to the limiting position shown, the carrier is swung in a corresponding direction and downward to project the nozzles into the shed and between the warp yarn. As the lay beam swings back toward the dotted line position idea, the nozzles are withdrawn from thewarp and the carrier is swung back to the dotted line position 25a, by means of spring '46 attached to one of the arms 28.

The drying oil pump 39, acting to discharge fluid from the nozzles 3| under intermittently applied pressure impulses, comprises, typically, a shell Al forming an oil reservoir, and a cylinder 33 communicable through opening M with conduit 28. The liquid is taken into the cylinder chamber through ports 45 and is discharged to the nozzles by plunger 55, the rod 41 of which extends through the packing gland 58 in the top closure 59. Coil spring 50 acts to maintain the head 5| of the plunger in engagement with an arm 52 projecting from the lay beam IE3. Check valves .53 and '54 are located in the plunger and pump outlet, respectively, the latter acting to prevent return flow from the pipe 28 during the suction stroke of the plunger.

In the operation of the machine, assuming the lay beam and carrier 26 to be moving from the dotted toward the solid line position, the operation of the pump 39 is so timed relative to the travel of the carrier that at substantially the point at which the nozzles 3! first enter the upper warp course 15, the plunger 6.6 will have moved down past the openings 45 to discharge the drying oil through pipe 28 and openings 33 in opposite sides of the nozzles. The latter have a wiping action between the yarns of the warp and cause the drying oil to thoroughly contact and impregnate the yarn. Discharge of oil from the nozzles continues until the latter reach their lowermost positions in the shed, at which point the lay beam starts its return movement toward the right, plunger it rises under the influence of spring 58, and check valve 5 seats to prevent return flow .into the cylinder.

Following withdrawal of the nozzles from the warp, shuttle i8 traverses the shed and extends the weft yarn is across the warp at the weave point 2-8 to be contacted and compacted into the weave by'the reed W. The drying oil, having been deposited in advance of the weft, is driven into the weave by the action of the reed and caused to thoroughly permeate the weft yarn.

instead of using a pump of the general type shown in Fig. 5 for the purpose of accomplishing an intermittent discharge of fluid from the nozzles, I may maintain the body of the .oil under sufficient discharge pressure and effect the intermittent discharge by a valve mechanism operated in timed relation with the weaving operation. For example, the drying oil may be maintained ina reservoir 55, see Fig. 6, under constant air pressure communicated through line 56. Intermittent discharge of oil from the reservoir is controlled by a valve 57 having a passage 58 adapted to .be brought into registration with port 5% in the wall of cylinder 68 when the valve rod 6! is depressed by the .lay beam arm 52 as in the previously described form. Here the discharge of oil from the nozzles will continue while the nozzles are moving into and out of the shed and during the period .of registration between passage 58 and port 59..

In addition to liquid substances such as drying oil, Imay incorporate in the lining finely divided solids such as graphite, silica, soft metals such as lead and zinc .or compounds of the metals. In some instances impregnation with solids may .be desirable for the purpose of giving greater body to the lining and to attain certain frictional characteristics. The solids may be applied to the lining forming material in any suitable manner, but preferably they are projected against the yarns after the latter have been coated with oil, thereby utilizing the oil as a medium for holding the solid particles to the yarn. Preferably,

I feed the solids into the warp near the weave point according to substantially the same method followed in applying the drying oil.

The pulverulent solid material is contained in a compartment 2% in the carrier 21 separate from the dryingoil compartment 21a. The solids are discharged through nozzles 63 located in advance, that is toward the weave point Zll, of the liquid discharge nozzles 2!. Compressed air is intermittently discharged from nozzles 64 into the upper venturi-shaped ends of nozzles 63, air being supplied through line 65 from a compressed air source, not shown. Air is intermittently injected into the upper ends of nozzles 63 under control of valve 66 operated in timed relation with the movement of the lay beam. Valve 66 comprises a plunger 61 operated by rod 68 intermittently moved toward the left by arm 69 carried on the lay beam. As the latter reaches a position corresponding to the points at which nozzles 63 start to enter the shed, valve port 10 is brought opposite body port H to cause a high velocity stream of air to be projected into the upper end of nozzle 63. As a result of rapid reciprocating movement of the carrier, the pulverized solids '52 are maintained in such a state of agitation that the projected air stream carries a portion of the dust through the nozzle and side opening it and deposits the solid particles on the yarns at opposite sides of the nozzles. As the nozzles leave the shed, valve 6'! is moved toward the right by spring 74 to cut off ports 10 and discontinue the flow of air to the carrier.

After being thoroughly impregnated in the manner described, the woven lining is taken to a baking oven and heated to a temperature of from 300 to 450 F. As previously mentioned, the oven may be immediately brought up to temperature and the lining rapidly heated to completion of the baking operation in a comparatively short time, by reason of the fact that the usual care and delay may be avoided due to the absence of solvent in the lining. As will be apparent from the foregoing, the entire simple impregnating and baking operations may be completed in a comparatively short length of time to the production of the finished lining.

I claim: 7

l. The method of making woven friction linings that includes, advancing upper and lower courses of warp yarns toward the weave point, and incorporating in the lining a substance adapted to give the lining predetermined frictional characteristics, by applying said substance through separate passages extending between'the yarns of both of said courses.

2. In apparatus of the character described, means for advancing upper and lower courses of warp yarns toward a weave point and for weaving the yarns, a plurality of nozzles for discharging material against said yarns, means for projecting said nozzles through both of said courses at predetermined intervals, and means for discharging material from the nozzles under intermittently applied pressure impulses.

3. The method of making woven friction linings that includes, advancing upper and lower courses of warp yarns toward the weave point, and incorporating in the lining a substance adapted to give the lining predetermined frictional characteristics, by intermittently projecting a conduit between adjacent yarns of one of said courses and flowing a single stream of said substance from the conduitagainst said adjacent yarns from a point between them.

' 4: In apparatus of the character described, means for advancing upper and lower courses of warp yarns toward a weave pointpa conduit mounted for movement between adjacent yarns of one of said courses into and out of the shed between them, there being "fluid delivery orifices in opposite sides of the conduit and from which fluid is discharged laterally against the yarn, and means for actuating said conduit.

5. The method of making woven friction linings that includes, weaving upper and lower courses of warp yarns converging toward a weave point, wetting the yarns by applying to the convergent warp courses a liquid substance, and then immediately applying a pulverulent solid substance to the wetted yarns at a point in close proximity to said weave point.

6. The method of making woven friction linings that includes, weaving upper and lower courses of warp yarns converging toward a weave point, wetting the yarns by applying to the convergent warp courses a liquid substance, and then immediately and intermittently applying a pulverulent solid substance to the wetted yarns at a point in close proximity to said weave point in timed relation to the weaving operation.

7. The method of making woven friction linings that includes, weaving upper and lower courses of warp yarns converging toward a weave point, wetting the yarns by applying to the convergent warp courses a liquid substance, and then immediately applying a pulverulent solid substance to the wetted yarns at a point in close proximity to said weave point, both said liquid and solid substances being intermittently applied in timed relation with the weaving operation.

8. In an apparatus for making woven friction linings, the combination comprising, means for weaving upper and lower courses of warp yarns converging toward a weave point, means for applying to the convergent warp courses a liquid substance to wet the yarns, and means for separately applying a pulverulent solid substance to the wetted yarns at a point between said weave point and the point of application of said liquid. 9. In an apparatus for making woven friction linings, the combination comprising, means for weaving upper and lower courses of warp yarns converging toward a weave point, means for applying to the convergent warp courses a liquid substance to wet the yarns, and means for separately applying a pulverulent solid substance to the wetted yarns at a point between said weave point and the point of application of said liquid, the last mentioned means operating to apply said solid substance intermittently in timed relation with said weaving operation.

10. The method of making woven friction linings that includes, weaving upper and lower courses of warp yarns converging toward a weave point, wetting the yarns by applying to the convergent warp courses a liquid substance, and then immediately applying a pulverulent solid substance to the wetted yarns at a point between said weave point and the point of application of said liquid.

11. The method of making woven friction linings that includes, weaving upper and lower courses of warp yarns converging toward a weave point, wetting the yarns by applying to the convergent warp courses a liquid substance, and then immediately and intermittently applying a pulverulent solid substance to the wetted yarns at a point between said weave point and the point of application of said liquid.

12. Inan apparatus :for making woven friction lining-s, the combination comprising, means for weaving upper and lower courses of warp yarns converging .towarda Weave point, means for ap- 5 plying to the convergent Warp courses a liquid substance to wetthe yarns, and means for separately applying a pulverulent solid substance to the wetted yarns at a point between said weave point and the point of application of said liquid, both said means operating to apply said substances intermittently and in timed relation with said Weaving operation.

DONALD W. FETHER. 

